What term describes the smallest units of sound blended to create words?

The term that describes the smallest units of sound blended to create words is phonemes. Phonemes are the distinct units of sound in a specified language that can distinguish between words. For example, in the word "bat," the sounds /b/, /a/, and /t/ are all phonemes. Each of these sounds contributes to the meaning of the word, and changing any one of them would result in a different word, such as "cat" or "pat."

Onsets refer to the initial consonant or consonant cluster of a syllable, which does not encompass the full range of sounds in a word. Morphemes are the smallest units of meaning in a language, which can include whole words or prefixes and suffixes, thus focusing more on meaning than sound. Syllables are units of sound that typically contain a vowel sound and may include surrounding consonants, but they consist of larger sound units than single phonemes. Hence, phonemes are specifically the building blocks of sound used to construct words.